This invention relates to an apparatus and a method for automatically sewing portions of a garment. In particular, the invention concerns an apparatus and a method for sewing garment portions along seams which follow seam tracks on the garment portions having different curvatures.
My copending application, Ser. No. 571,120, filed on Jan. 17, 1984, (the disclosure of which is hereby incorporated by reference herein) describes an apparatus for automatically mating and sewing together fabric plies, which are to form part of a garment. In the apparatus described therein, the fabric plies are sewn along a curved seam track that follows a curved path which has the same curvature on each ply when the two material plies to be mated are flat and relaxed (not stretched) in their mated configuration. Accordingly, the material plies can be placed together automatically in a flattened condition, transported together to a sewing machine and past the sewing head of the sewing machine, thereby forming a seam along the seam track between the fabric plies.
In addition to such simple sewing operations, the fabrication of clothing requires more complex sewing operations wherein material plies must be joined along seam tracks which follow a different curvature on each of the plies. For purposes of example, the seam which joins the shoulder of a T-shirt to the sleeve of a T-shirt must be sewn along a seam track on the mated front and back of the T-shirt, which can be described as a "concave" edge, labeled 20 in FIG. 11. The concave edge 20 must be mated and joined to what will be described as a convex edge 22, which is visible in FIG. 11 for the sleeve ply in the relaxed state.
The sewing operation to join the sleeve to the shirt front and back is normally performed by a sewing machine operator, who must bring the edges together along the seam track as the sewing operation progresses. It is an object of the present invention to provide a machine which will automatically mate plies along the different seam track and join the plies following a different seam track curvature on the two plies.